Protection Of Glutamine Induced Hsp70 On Intestinal Mucosal Mechanical Barrier In Acute Heat Stressed Goose

The aim of this study was to investigate the protective effect of glutamine(Gln)induced Hsp70 on Intestinal Mucosal Mechanical Barrier in Heat Stressed Goose the intestinal epithelial mucosal barrier system.Intestinal structure,relative expression of Claudin-1?Occludin?ZO-1 protein and mRNA in jejunum,diamine oxidase(DAO),D-lactic acid(DLA),lactate dehydrogenase(LDH),corticosterone(CORT),creatine kinase(CK),triiodothyronine(T3),and thyroid(T4)in blood,were determined for this purpose.Experiment one,Establishment of upregulated expression model of Hsp70 in intestinal of geese.A total of 60 1-day-old Jilin white geese were randomly divided into six treatment groups: in a completely randomized design 6 replications with 1 goose in each replication.On the 69 th day,geese in the different group were intraperitoneally injected per kg of body weight with Gln liquid: 0g,0.35 g,0.55 g,0.75 g,0.95 g,1.15 g.After 24 hours,slaughtered the geese.The relative expression levels of Hsp70 were determined by scraping the jejunal epithelial mucosa.The result shows that Gln induced Hsp70 and the expression depends on concentration of Gln(P<0.01).Based on the comprehensive literature and research results,0.75g/kg was selected as the dose concentration of the upregulation expression model of Hsp70 in subsequent experiments.Experiment two,Protection of Gln induced Hsp70 on intestinal mucosal mechanical barrier in heat stressed goose.A total of 180 1-day-old Jilin white geese were randomly divided into CON group,HS group,GLN group,in a completely randomized design 6 replications with 10 geese in each replication.On the 69 th day,geese in the CON group and the HS group were intraperitoneally injected with normal saline,and those in the Gln group with Gln(0.75 g/kg standard).After 24 hours,the geese in the HS group and the Gln group were subjected to heat stress treatment for 4 hours(41±1°C,relative humidity 60%),test the anal temperature and then slaughtered.Blood sample were collected for the deamination of DAO,DLA,LDH,CORT,CK,T3,T4 activity.Duodenum,jejunum,ileum were cut for the observation of intestinal structure,and jejunum were cut for the observation of ultrastructure by transmission electron microscope.The relative expression levels of Hsp70,Occludin,Claudin-1 and ZO-1 protein and mRNA were determined by scraping the jejunal epithelial mucosa.The results showed that the upregulation expression of Hsp70 had a significant effect on the blood indexes of geese under heat stress,which significantly enhanced the T3 activity in the blood(P<0.01),significantly decreased the activity of CK(P<0.01),LDH(P<0.01),T4(P<0.01),and CORT(P<0.01),and CK,LDH were restored to the CON group;Hsp70 higher expression can significantly improve Claudin-1(P<0.01),Occludin(P<0.01),ZO-1(P<0.01)protein and mRNA expression level of intestinal mucosa of the heat stressed goose,the effect of Claudin-1 is most obvious,followed by ZO-1;The experiment confirmed that the up-regulated expression of gln-induced Hsp70 can significantly alleviate the problem of increased intestinal permeability caused by heat stress in geese,maintain the integrity of intestinal mechanical barrier,and thereby protect the structure and function of intestinal mucosal barrier system.